Hi @SheilaZickefoos
What you're describing with the invitation that includes a password setup only occurs when instructors are adding new users to system at the same time that they are adding them to the course (Open Registration).
Enrolling existing users in a course would result in them being sent an invitation to join the course, but would not send them a link to set their password.
Generally speaking, users or enrollments created via SIS Import do not result in any kind of invitation being sent to the user. The only time that a user will be sent an invitation to set their password after having their account created via SIS Import is if the "canvas_password_notification" value is set to "y" in the user feeds file. See the various password options shown in the "Users.csv" section of https://canvas.instructure.com/doc/api/file.sis_csv.html
If users are supposed to use a local Canvas login (as opposed to an SSO), you probably want to be sure that the "authentication_provider_id" value is "canvas" in the feed file, or else I believe that Canvas assumes that a blank/empty password in the feed file implies that the password is coming from an SSO.